Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Assets	$ 48,936	$ 48,433
Variable Interest Entity, Primary Beneficiary [Member] | Cash and cash equivalents [Member]
Variable Interest Entity [Line Items]
Assets	33	49
Variable Interest Entity, Primary Beneficiary [Member] | Trade accounts and other receivables - net [Member]
Variable Interest Entity [Line Items]
Assets	156	136
Variable Interest Entity, Primary Beneficiary [Member] | Inventories [Member]
Variable Interest Entity [Line Items]
Assets	4	4
Variable Interest Entity, Primary Beneficiary [Member] | Other current assets and deferred charges [Member]
Variable Interest Entity [Line Items]
Assets	4	7
Variable Interest Entity, Primary Beneficiary [Member] | Property, plant, and equipment - net [Member]
Variable Interest Entity [Line Items]
Assets	5,123	5,154
Variable Interest Entity, Primary Beneficiary [Member] | Intangible assets - net of accumulated amortization [Member]
Variable Interest Entity [Line Items]
Assets	2,131	2,158
Variable Interest Entity, Primary Beneficiary [Member] | Regulatory assets, deferred charges, and other [Member]
Variable Interest Entity [Line Items]
Assets	30	29
Variable Interest Entity, Primary Beneficiary [Member] | Accounts payable [Member]
Variable Interest Entity [Line Items]
Liabilities	(74)	(76)
Variable Interest Entity, Primary Beneficiary [Member] | Accrued and other current liabilities [Member]
Variable Interest Entity [Line Items]
Liabilities	(33)	(34)
Variable Interest Entity, Primary Beneficiary [Member] | Regulatory liabilities, deferred income, and other [Member]
Variable Interest Entity [Line Items]
Liabilities	$ (275)	$ (275)
Variable Interest Entity, Primary Beneficiary [Member] | Williams Companies Inc [Member] | Northeast JV [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	65.00%
Variable Interest Entity, Primary Beneficiary [Member] | Williams Companies Inc [Member] | Gulfstar One [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	51.00%
Variable Interest Entity, Primary Beneficiary [Member] | Williams Companies Inc [Member] | Cardinal Gas Services LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	66.00%
Variable Interest Entity, Not Primary Beneficiary [Member] | Williams Companies Inc [Member] | Targa Train 7 LLC
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	20.00%
Equity Method Investments	$ 45
Variable Interest Entity, Not Primary Beneficiary [Member] | Williams Companies Inc [Member] | Brazos Permian II LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	15.00%
Equity Method Investments	$ 18